It is challenging for visually-impaired people to find their way in unfamiliar, complex indoor spaces such as schools or office buildings. GPS technology has already been exploited for speech-based navigation for visually-impaired wayfinding in outdoor environments, but there is no equivalent technology for indoor wayfinding. Sighted pedestrians may sometimes find indoor wayfinding challenging, but they can usually find their way with the help of signage. The inability to easily access signage continues to be a major impediment to indoor wayfinding for people with visual disabilities. A team at the University of Minnesota Laboratory for Low-Vision Research, first demonstrated the feasibility of a "Digital Sign System" (DSS) to support indoor navigation for visually impaired people. In Phase I, this team worked in partnership with AME Corp. to develop evaluation prototype of the DSS system, and demonstrated its use for non-visual indoor navigation with human performance tests. The DSS system consists of a hand-held device that emits an infrared beam. The user pans the beam until a reflection from a retroreflective bar-coded sign is returned. Computer software "reads" the sign's image and feeds its identification code to a building database. Information, including the content of the sign and its position, is then retrieved from the database and provided to the user via synthetic speech. Feasibility prototypes of all system components have been developed and validated. The goal of this phase II project is to develop a production prototype for human testing. The engineering work will include designing an improved optical assembly and developing digital tag localization software that runs on a digital signal process in real time in the prototype. This production prototype will be used to evaluate the efficacy of indoor wayfinding by visually impaired pedestrians via DSS and a spatial database with speech-based user interface called the Building Navigator. These production prototypes will be commercially viable. PUBLIC HEALTH RELEVANCE: Independent mobility is an important prerequisite for full participation in modern society. Reduced mobility and associated social isolation are among the most debilitating consequences of vision loss. The Digital Sign System is a significant new technology to assist wayfinding for people with vision loss because of the low cost required for a facility to implement it.